John Longworth may refer to:

• John Longworth (lawyer) (1814–1885), lawyer, judge and political figure in Prince Edward Island.
• John Longworth (businessman) (born 1958), British business consultant

• John Charles Fremont
• John Charles Frémont
• John Charles Haines
• John Charles Harsanyi
• John Charles Herries
• John Charles I of Spain
• John Charles Kaine
• John Charles Martin Nash
• John Charles McQuaid
• John Charles of Spain
• John Charles Patrick Croghan Daly
• John Charles Spencer, 3rd Earl Spencer
• John Charles Spencer, Viscount Althorp
• John Charles Thomas
• John Charles Walsham, 1st Baron Reith of Stonehaven Reith
• John Charles Walsham Reith
• John Charles Walsham Reith, 1st Baron Reith
• John Charlewood
• John Charlier de Gerson
• John C. Harsanyi
• John Chataway
• John Chatman
• John Cheever
• John Cheke
• John Chenoweth